The present invention relates to fatty alcohol phosphate ester emulsifier compositions useful in the preparation of oil-in-water emulsions and microemulsions. The present invention further relates to emulsifying waxes, oil-in-water emulsions and oil-in-water microemulsions prepared from the fatty alcohol phosphate ester emulsifier compositions of the present invention. The emulsions and microemulsions of the present invention are particularly useful in the formulation of topical cosmetic preparations, particularly hair and skin care products in the form of lotions, creams or gels.
Mixed phosphate esters of polyalkoxylated fatty alcohols such as are disclosed in U.S. Pat. No. 3,963,628 to Park and U.S. Pat. No. 4,369,134 to Deguchi et al. have been widely used in the personal care industry as emulsifiers for oil-in-water emulsions. However, such compounds possess less than desirable emulsion stability. Phosphate mono-esters of higher fatty alcohols, such as cetyl alcohol, have also become popular as emulsifiers, but they are used only as secondary or co-emulsifiers and require the use of primary emulsifiers to achieve emulsion stability.
Phosphate ester emulsifiers for oil-in-water emulsions having improved emulsion stabilizing properties would be highly desirable.